Halve vanilla bean lengthwise, scrape out the seeds, and cook seeds with the pod and poppy seeds in milk. Remove from stove and cool.

Cream the butter and sugar in a mixer until light and creamy. Thicken by adding eggs one at a time, mixing well after each addition until the egg is completely incorporated. Grate marzipan on a coarse grater and stir into egg mixture.

Sift flour, baking powder, and salt. Alternate adding the flour mixture and the cooled poppy-milk mixture to the butter mixture, stirring after each addition. Pour the batter into the prepared molds and bake about 17 minutes on medium rack. (Stick a wooden skewer into the cake; when it comes out clean, the cake is done.)

Let the cakes cool for a few minutes, then turn out from mold. Best served warm.

(The recipe says the cake is best warm but I think it tastes better cold, and it goes quite nicely with a cup of tea.)